As a technique of this type, Patent Literature 1 discloses a resolver of an electric motor which is used as a brushless motor. As shown in FIG. 16 of this application, a conductive harness connection terminal 100 around which a resolver winding is wound is embedded in a terminal holding portion 101 which is made of resin. The terminal holding portion 101 has an opening 102 formed therein to allow the harness connection terminal 100 to be exposed. A connection portion 104 is attached to a sensor terminal 103 for deriving an output signal from the resolver. The connection portion 104 is composed of a wide portion 105 and a disc portion 106. Protrusions 107 are integrally formed on both sides of the wide portion 105 in the width direction thereof. When the connection portion 104 is fitted into the opening 102, the protrusions 107 are press-fitted into the opening 102. After that, the disc portion 106 of the connection portion 104 is spot-welded to the harness connection terminal 100.